An "Unnatural" Landscape

During the last century, Gross Reservoir was built upstream. Large spring floods and sediment no longer came downstream. The creek eroded its channel deeper. The ditch company built a diversion dam because its headgate was suddenly above the creek level. Exotic species such as green ash and crack willow colonized South Boulder Creek. Taken all together, this explains why the creek is narrower now, and why there are so many more trees today.